HUDSONVILLE – A team of extra custodians was brought in Wednesday to start disinfecting Unity Christian High School classrooms, said principal Jack Postma.

Classes were canceled Wednesday and Thursday after a growing number of students were calling in sick. On Tuesday, almost a quarter of the school's students were ill.

The Ottawa County Health Department, which is working with the school to make sure the disease doesn't spread further, suggested the school close for two days while students recover. In the meantime, the department is in the process of collecting virus samples from students, said spokeswoman Shannon Felgner.

Samples will be taken the Michigan Department of Community Health on Friday, she said, and results may come back on Monday.

So far, all health department officials know is that the illness is gastrointestinal, Postma said, with students experiencing vomiting and diarrhea for one to two days.

“Our hope and prayer is our kids are getting healthier,” he said.

None of the school's staff was affected by the illness, but offices will be disinfected on Thursday, Postma said.